Direct thermal printers equipped with a line thermal head have been well known. Into such a direct thermal printer, a plurality of heat-sensitive sheets in the form of cut sheets are stacked up and loaded.
The printer is provided with a pickup roller so as to make contact with one side of the stack of sheets set in a sheet storage unit of the printer. Each sheet is extracted from the stack by the revolution of the pickup roller and fed to a print mechanism unit one by one. In the print mechanism unit, each line on the sheet orthogonal to the sheet feed direction is heated by the thermal head, by which arbitrary letters, images, etc. are printed on the sheet.
In the vicinity of the pickup roller, a block part having a separation guide surface being tilted with respect to the sheet feed direction is placed. The separation guide surface, with which the front end of the sheet extracted from the stack by the pickup roller makes contact, exerts proper frictional force on the front end of the sheet and thereby performs a function promoting the separation of the sheets. Consequently, the sheets are separated from the stack one by one and fed toward a sheet supply side of the print mechanism unit.